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Rémi Loire



From flushing flows to (eco)morphogenic flow releases : evolving terminology, practice, and integration into regulated river management.


Over the centuries, many rivers have been regulated by dams to meet various needs such as flood management, hydropower production, irrigation, drinking water supply, etc. Today, in the northern third of the planet, 77% of watercourses are affected by dams and a very large number are under construction or planned in the coming decades. The impacts of dams, particularly those with the largest reservoirs, are now well-known. Their influence, more or less pronounced, can affect floods (flow, frequency, peak and duration), which results in a change of the occurrence of the natural "channel morphing discharge" in the downstream reaches. The result is a modified river morphology and dynamics, with impacts on biological communities and uses. In order to improve/restore aquatic and riparian environments, dam managers are increasingly being asked to generate high flows, known as "flushing flows” or “ecomorphogenic flows”, from their dams.This thesis focuses initially on clarifying the concepts of discharge, water release, and "ecomorphogenic flows”. A new terminology has been proposed that fits into the broader context of “environmental flows” and “ecological flows”. In a second step, previous works and experiments carried out on the Durance River, the Selves River and the Isère River provided elements to build a methodology for implementing ecomorphogenic flow releases as part of adaptive management. This operational methodology is based on a series of successive steps resulting from a preliminary diagnosis. It makes it possible to determine the parameters necessary for designing releases, identifying constraints and defining expected results (target compartments, orders of magnitude of process, etc.) to evaluate the efficiency of the operation. Finally, through the implementation of trigger indicators, it provides evaluation information to decide whether to renew, or improve releases or to replace them with other management actions.

Key words

Dam, environmental flow, water release, flushing flow, channel maintenance flow, morphogenic flow releases, ecomorphogenic flow releases, adaptive management, river restoration, sediment transport

H2O'Lyon theis Director

Hervé Piégay, CNRS, ENS Lyon

Doctoral School

ED 483 - Social Sciences


ENS Lyon

Defence date

6 september 2019

Defence language


Thesis jury members

  • Emmanuèle Gautier, Professor, Université Paris 1, rapportrice
  • Stéphane Rodrigues, Professor, Université de Tours, rapporteur
  • Askoa Ibisate, Professor, Université du Pays Basque, examinatrice
  • Gabriel Melun, PhD, Agence Française pour la Biodiversité, examinateur
  • Jean-René Malavoi, Doctor, EDF, thesis co-director
  • Hervé Piégay, ENS, CNRS, thesis director.